Typewriting machine



Feb. 9, 1937. H. L. PITMAN 25 TYPEWRITING MACHINE Original Filed Sept.21, 1933 INVENTOR ATTOZEY Feb. 9, 1937. H. L. PITMAN 'IYPEWRITINGMACHINE Original Filed Sept. 21, 1955 2 Sheets-Sheet 2 R O T N E V mATTOR Patented Feb. 9, 1937 UNITED STATES PATENT or ies TYPEWRITINGMACHINE Original application September 21-, 1933, Serial N 0. 690,301.Divided and this application September 30, 1935, Serial No. 42,808

6 Claims.

This invention relates to universal-bar mechanism for theribbon-vibrator and escapement of typewriting machines, and one of itsaims is to eliminate the liability of overthrowing or crumpling thevibrating ribbon.

It is usual for a common universal-bar stroke to effect simultaneouslythe escapement-operation and full amplitude of ribbon-vibration, theStroke having the high speed or staccato characteristic due thedesirability of working the escapement quickly. Because the ribbon isvibrated very fast, it is liable to overthrow, which causes bleeding ina two-color ribbon. It is further liable to crumpling, which, at highspeed, is due to inertia of the ribbon relatively to the rapidlystarting ribbop-vibrator.

It remains desirable to localize the universalbar mechanism at theregion of the machine where it can be operated by a type-carrier which,swinging in the usual Wide arc, is the member best capable, by reason ofits momentum at the end-portion of its swing followed by immediaterecoil, of imparting the desired staccato impulse to the universal bar.

In the standard Underwood typing machine, for example, each of thearcuately-arrayed swinging type-bars has near its fulcrum a heel toactuate a single curved universal bar common 3 to the escapement andribbon-vibratingdevices,

and which universal bar, in order to secure its staccato actuation, isonly engaged by said heel at the final portion of the printing stroke.It Will be evident that when such common universal bar 35 andcooperating heel are used, the limit to which the speed ofribbon-vibration can be forced, limitedly determines the speed of theuniversal bar and hence, largely, the speed of the carriageeed.

In practicing the present invention, a univere sal-bar-actuating portionof the type-bar or other similarly moving type-action member is arrangedrelatively to a novel localized universalbar mechanism in such a waythat the ribbonmovement to the printing point does not wait for thecarriage-escapement operation, but starts substantially as soon as thetype-bar leaves its normal position, and may continue substantiallythroughout the printing stroke. The movement of the ribbon to theprinting point is thus protracted, and it may be effected with smoothacceleration. Thus there is eliminated the liability of eitheroverthrowing or crumpling the ribbon. Said universal-bar-actuatingportion of the typeaction member is further arranged relatively to thenovel localized universal-bar mechanism, so that theescapement-actuating phase in the operation of said mechanism has thedesired staccato characteristic, whereby the escapement is actuated inimmediate correlation to, that is, very close to, the instant oftype-impact, and it is feasible therefore to use a speed escapement withconsequent benefit to the key-touch.

To these ends, the universal bar is preferably made in two parts, whichparts present two universal'faces or edges which may be disposed next toone another in accordancewith the idea of localizing the universal-barmechanism. One of the parts has its universal face or edge engagedpreferably bya cam on the swinging typebar or similarly movingtype-action member, and operative to impart the relatively slow movementto said ribbon-vibrating universal-bar part. The other universal-barpart. is. engaged by a formation on the type-action member, so disposedthat it comes into play very close to the instant of type-impact, sothat the desired quick operation of the carriage-escapement is effected.

In the Underwood type of machine, the twouniversal faces or edges may bearcuate to conform with the arcuate array of the type-bars, each of thelatter being provided with said ribhon-vibrating cam and saidescapement-actuating formation. Said arcuate universal-bar parts may beone above the other.

The arrangement may be such that the connections to operate thecarriage-escapement and ribbon-vibrator may remain practically unalteredin respect to the connections used in prior machines, and the noveluniversal-bar mechanism may therefore be applied to existing types ofmachines at little expense.

The invention may be used in the form of a single universai bar having auniversal face or edge formation, which is engageable, during theprinting stroke, first by the protractedly-operating ribbon-vibratingcam of the type-action member, and then by a part on said type-actionmember, which part overhauls the single universal bar and gives the samea staccato impulse very close to the instant of type-impact, and, at thebeginning of which impulse, said universal bar has reached the end ofapproach to, and has thereby become engaged with, acarriage-escapement-operating member.

This application is a division of my application Serial No. 690,301,filed September 21, 1933" (now patent No. 2,023,487, dated December 10,1935).

Other features and advantages will hereinafter appear.

In the accompanying drawings,

Figure 1 is a perspective view showing the invention as applied to asingle universal bar.

Figure 2 is a side elevation view showing the single universal bar andits relation to the novel type-bar heel and to the ribbon-vibrating andescapement-operating connections. Figure 3 is a front elevation view ofparts of the organization seen in Figure 2, some of said parts beingsectioned and broken away for clearness.

Figure 4 is a side elevation of the universalbar train and connectionsof Figure 2, and shows the positions of the parts at the instant oftypeimpact.

Figure 5 is a fragmentary side view indicating how the type-bar heel-cammay effect the ribhon-vibrating phase of universal-bar movement, andalso indicating, in the use of asingle universal bar, how theescapement-actuating portion of said heel has overhauled the coactingedge of the single universal bar.

Depression of any alphabet or numeral typekey I0 on key-lever I I,Figure 2, swings, by means of suitable connections, a type-bar I3,pivoted at I4, to print against aplaten I5. Said connections may includea bell-crank I'I articulated to the 1 key-lever II by a pin-and-slotconnection I9 and to the type-bar I3 by a link 20, as examplified inPatent No. 644,082, to Kauffman, of February 27, 1900.

A segment ZI on machine-frame 22 pivotally mounts the system oftype-bars I3 in the usual arcuate array seen in Figure 3.

An Underwood platen-carriage is represented in Figure 2 by acase-shiftable frame 24 forming part of said carriage which has aletter-feeding rack 25 and is driven by the usual spring-motor (notshown) in a letter-feeding step at operation of a type-bar I3.

The novel ribbon and escapement actuating universal-bar mechanism willnow be described with reference to its application in the illustratedmachine. It may be noted beforehand that the escapement-mechanismincludes the usual escapement-wheel 28 co-operative with the usualdog-rocker 29 having dogs 3| and 32, said escapement-wheel having apinion 33 meshing with the carriage-rack 25.

For the purpose of vibrating the ribbon at relatively slow speed and theescapement at high speed by means of a localized universal-barmechanism, the invention may be practiced by' means of a substantiallyone-piece or unitary universal bar or frame, which, to this end, maybearranged relatively to the type-bar I3, as shown in Figures 1 to 5. V

The heel-portion of each type-bar I3 is accordingly made substantiallythe same as hereinbefore described, to include a ribbon-vibratingcamming edge 62 and an escapement-actuating 'The edge or face I03;associated with operation of the ribbon-vibrator, may be formed by aflange I00 of an arcuate bar I01. A similar bar I08 presents the edgeI05 which is associated with operation of the escapement.

Said bars I01, I08 and a member III are fastened together by rivets I I0to form the universalbar frame I 04 which has side arms I I3 connectedto the rockable frame 46 to support the rear of the frame I04 forfore-and-aft movement. The forward part of said frame I 04 is supportedfor fore-and-aft movement by means of a tongue I I 4, slidably fittingin segment 2| A spring I I6 urges the universal-bar frame I04 forwardly,the forward movement of said frame being limited, as in Figure 2, byabutment of the face I03 thereof with the camming edge 62 of thetype-bar.

The universal-bar-frame member II I also has an upstanding flange II! tocarry the laterallyshiftable bracket 73 of the usual Underwoodribboil-vibrating train.

In the swing of the type-bar I3 from the Figure 2 position to the Figure5 position, and beginning with the start of said swing, the camming edge62* of said type-bar moves the universalbar frame I04 rearwardly withsmooth acceleration indicated by the dotted lines I I8, Figure 5representing the positions of the frame I94 at equally spaced stages inthe swing of the type-bar. Hence the cam-edge 63* here, too, co-operatesto raise the ribbon without liability of overthrowing or crumpling thesame. As indicated in Figure 2, an escapement-actuating rear edge i I 9of the frame I04, opposite the dog-rocker 29, is normally spacedforwardly of said dog-rocker, so that the latter is not moved until thetype-bar reaches the Figure 5 position. The escapement-dog rocker 29 istherefore operated quickly, that is, in the relatively brief intervalduring which the type-bar I3 moves between the Figure 5 and the Figure 4positions. This quick movement of the universalbar frame I04 is effectedby means of said edge during said interval. Although the ribbon stillhas a residue of its movement to the printing point to be completedduring said interval, the liability of overthrow or crumpling of the'ribbon is, nevertheless, practically eliminated since said residue ofmovement is small, and hence the speed of the ribbon during saidinterval is very much less than where, as heretofore, the full amplitudeof ribbon-vibration took place during said interval. Conversely, duringthe recoil stroke of the type-bar from the Figure 4 po sition, theuniversal-bar frame I04 at first moves quickly forward under the pull ofspring II6 as the type-bar moves from the Figure 4 to the Figure 5position, and, in this part of the typebar recoil stroke, the dog-rocker29 quickly completes its reciprocatory movement. As the typebar furtherreturns, from the Figure 5 position to the Figure 2 position, theuniversal-bar frame I04, still moving forward under the pull of springH5, follows the camming edge 62 so that the return of the ribbon fromthe printing point is effected at relatively slow speed.

U. S. Patent 926,050, to F. A. Cook, exemplifies the Underwoodribbon-vibrator connections in which platen case-shift rail 64 mounts alever having an arm 68, carrying the ribbon-vibrator 35, and an arm 10presenting pins'II selectively engageable by laterally shiftable bracketI3 (Figure 3) on the universal bar frame flange H1. The bracket I3 inthe dotted-outline position 13 Figure 3, engages the upper pin H andhence rearward movement of the universal bar frame I04 will raise theribbon-vibrator 36 only far enough to make the upper band of a two-colorribbon 21 effective. With the bracket 73 in the full-line position ofFigure 3 to engage the lower pin "H, the rearward movement of theuniversal bar frame I04 brings the lower ribbon band to the printingpoint, Figure 4. The usual linkage for shifting bracket 13 isrepresented at 18.

It will be seen that the novel universal-bar mechanism is localized sothat it occupies very little more room than was heretofore occupied bythe single Underwood universal bar; and it will be further seen that theconnections from said mechanism to the ribbon-vibrator 36 and theescapement-dog rocker 29 may be arranged as in prior machines, and thatthe invention may therefore be applied at little expense.

Variations may be resorted to within the scope of the invention, andportions of the improvements may be used without others.

Having thus described my invention, I claim:

1. In a typewriting machine, a system of members ofindividually-operable type-actions, and a universal-bar device foractuating the ribbon-vibrator and carriage-escapement of said machine,each member having means for actuating the ribbon-vibrator at relativelyslow speed by Working said universal-bar device through a protractedperiod of the type-action stroke, each member also having a shouldercoming into play to actuate said universal-bar device to work theescapement quickly in correlation to the instant of typeimpact, saiduniversal-bar device being arranged so that the points at which it isengaged by each of said means and corresponding shoulder are juxtaposed,next to one another, to localize said points and thereby compact saiddevice.

2. In a typewriting machine, a system of members ofindividually-operable type-actions, and a universal-bar device foractuating the ribbonvibrator and carriage-escapement of said. machine,each member having a cam for actuating the ribbon-vibrator at relativelyslow speed by working said universal-bar device through a protractedperiod of the type-action stroke, each member also having a shouldercoming into play to actuate said universal-bar device to work theescapement quickly in correlation to the instant of type-impact, saiduniversal-bar device having two faces, one face for engagement by saidcam, and the other face for engagement by said shoulder, said facesbeing juxtaposed, next to one another, to localize the same and therebycompact said device.

3. In a typewriting machine having a ribbonvibrator and anescapement-mechanism, a system of type-carriers mounted to swingindividually to bring their types to a common printing point, and auniversal-bar device operable to actuate the ribbon-vibrator andescapement, each type-carrier having at its fulcrum-end a cam to operatesaid universal-bar device through a protracted period of thetype-carrier stroke, each type-carrier also having near its fulcrum-enda shoulder coming into play to actuate said universal-bar device to workthe escapement quickly in correlation to the instant of type-impact,said universalbar device having means engageable by the cams andshoulders, and localized in operative contiguity thereto.

4. In a typewriting machine having a ribbonvibrator and anescapement-mechanism, a system of type-carriers mounted in arcuate arrayto swing their types to a common printing point, each type-carrierhaving at its fulcrum-end a cam, and also having a shoulder in sequenceto the cam-contour, and a universal-bar structure operable to actuatethe ribbon-vibrator and the escapement, said structure presenting acurved universal-bar portion for engagement by said cams and shoulders,the cam actuating the rib hon-vibrator at relatively slow speed byengaging said curved portion during a protracted period of the printingstroke, and the shoulder thereupon coming into play with said curvedportion to work the escapement quickly in correlation to the instant oftype-impact.

5. In a typewriting machine, a system of typeaction members swingable tobring types to and from the printing point, each of said type-actionmembers having coaxial with its fulcrum a twopart cam, a universal bardisplaceable by the rotation of any cam, and a letter-feeding escapementand a ribbon-vibrator operable by said universal bar, said cam anduniversal bar being relatively constructed so that the universal barstroke is smoothly accelerated, by one part of the cam, from thebeginning of and during a major portion of the printing stroke of thetype-action member, and is then abruptly stepped up in speed, by anotherpart of the cam, relatively to completion of the type-action memberprinting stroke, for eifecting, respectively, overthrow-preventingprotraction of the ribbon-vibrator operation, and staccato high-speedoperation of the letterfeed escapement.

6. In a typewriting machine, a system of typeactions printingindividually at a common printing point, a universal bar, aribbon-vibrator and an escapement mechanism operable by said universalbar, each type-action having two-part universal-bar-actuating means, onepart serving for smoothly accelerating the universal bar stroke from thebeginning of and during a major .portion of the printing stroke of thetype-action, the other part then coming into play to abruptly impel theuniversal bar to a substantially higher speed during the remainder ofthe printing stroke, whereby, respectively, overthrow-preventingprotraction of the ribbon-vibrator operation and staccato high-speedoperation of the letter-feed escapement are effected by means of saiduniversal bar.

HENRY L. PITMAN.

